Orb expertise needed.

Read the forum code of contact

Member for

17 years 11 months

Posts: 552

Orb expertise needed. Can anyone tell me what the "X" numbers mean that are allocated to each aircraft and crew of this orb? Individual radio call signs perhaps?

Attachments
Original post

Member for

17 years 11 months

Posts: 552

Bumping this one up again in the hope someone can answer my query.

Thanks, David

Member for

24 years 2 months

Posts: 855

Movement Serial Indicator issued by the Movement Liaison Section.

Used to classify RDF plots.

Ross

Member for

17 years 11 months

Posts: 552

Thanks Ross. Could you please explain that in layman's terms.

Member for

24 years 2 months

Posts: 855

What it says on the tin.

If you wanted to move an aircraft by air in wartime before you took off you applied to the Movement Liaison Section for a Movement Serial Indicator and to tell them your route with approximate timings. The MLS gave you next available serial from a letter/number sequence and recorded your details on a list which was sent to all filter rooms.

When the aircraft was picked up on RDF/Radar/Observer Corps and reported as unknown to filter room the duty Movement Liaison Officer looked up his list for who was authorised to be there and said either "friendly MSI - disregard" or "hostile - engage".

Ross

Member for

17 years 11 months

Posts: 552

Thanks Ross.

Member for

18 years 11 months

Posts: 8,847

That was very interesting and informative, thanks.